1. Field of Invention
The invention relates to a method for improving EMC (Electromagnetic Compatibility) and, in particular, to a method for improving the EMC on keyboard soft boards.
2. Related Art
Current electronic devices often need to be able to generate high-frequency signals due to the high-speed and digital requirements. The production of such high-frequency signals may cause EM (Electromagnetic) radiation due to the antenna effect from its circuit. In other words, the high-frequency circuits often become antenna themselves. Therefore, the designer has to take into account these effects, making sure that no high-frequency signals are radiated out to result in undesired EMI (Electromagnetic Interference) inside the electronic device. The requirement of EMC (Electromagnetic Compatibility) is thus demanded.
This kind of EMC requirement also applies to keyboard products. To satisfy the EMC requirement, normal keyboards have to be able to remove noise signals from its circuit. A common method is to provide EM protection, such as a metal shielding or grounding the system. However, installing a metal shielding makes the keyboard heavier and is thus inconvenient in use. Grounding the system imposes extra design costs on the keyboard. Consequently, a simple and cheap method developed to improve the EMC in the keyboard circuits is desired.